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Comment by WalterBright | Hacker News Reader

C++ should copy D's elegance:

    import std.stdio;

    string[9] vec = [ 
      "the", "quick", "brown", "fox", 
      "jumped", "over", "the", "lazy", "dog" 
    ];

    void main()
    {
      foreach (i, s; vec)
        writeln(i, ": ", s);
    }

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Although D is a strongly typed language, it is very good at type inference. The `s` is inferred as `string`, and `i` as `size_t`.

Go is similar:

  package main

  import "fmt"

  var vec = []string{"the", "quick", "brown", "fox", "jumped", "over", "the", "lazy", "dog"}

  func main() {
    for i, s := range vec {
      fmt.Printf("%d: %s\n", i, s)
    }
  }

Using `fmt.Println(i, ":", s)` inserts spaces on both sides of the colon, so the output is not quite right.

I find Go's `range` syntax easier to read than D's `(i, s; vec)` -- although generator functions that work with `range` have unaesthetic return types.

D has several usages for `foreach` depending on the number and type of its arguments. In this case, it sees that `vec` is an array, and so constructs a loop over the array. If `vec` was a range, the loop will be constructed as a loop over the array.

It's nice because it makes the syntax for arrays and ranges interchangeable, making for easy refactoring.

Go is similar: `for/range` has always worked on arrays, slices, maps, strings and channels, and they extended it to integers in version 1.22 and to user-defined generators in version 1.23. It generates one or two outputs depending on the type of the RHS, but one can assign the index value to _ to ignore it. Among standard types, only channels and integers generate one output; containers (including strings) give an index or key and a value.

I find Go’s version worse in that it does not allow you to elide the index (which is not needed most of the time). You have to write `for _, s := range vec`, as `for s := range vec` makes s the index.

To clarify,

    foreach (s; vec)

works if you don't need the index. To be able to modify s in place:

    foreach (ref s; vec) s = "replacement";

I was talking about Go. I know you don’t need the index in D.

C++23 example,

    import std;

    using namespace std;

    int main() {
        vector vec = { 
            "the", "quick", "brown", "fox", 
            "jumped", "over", "the", "lazy", "dog" 
        };

        for (auto&& [i, it] : vec | std::views::enumerate)
            println ("{}:{}", ++i, it);
    }

As I keep mentioning, the features being copied, slowly erode D's relevance.

If you prefer writing:

    for (auto&& [i, it] : vec | std::views::enumerate)
        println ("{}:{}", ++i, it);

instead of:

    foreach (i, s; vec)
        writeln(i, ": ", s);

well, what can I say?

We may first need to go over what "elegant" means I guess. :)

There is elegant when writing code by hand, and when reviewing code by AI agents.

I prefer to use the option with better market share.

I am not counting characters, especially when AI completes typing for me.

I don't like that semi-colon. AFAICT `i, s;` is not an independent statement. `i, s: vec` would have been fine, but `;` ?!?! madness.

Well, others might have said `i, s:` is not an independent label.

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